How to achieve proper focus of stars at night?

I would like to take some photos of stars at night. I have found the location. No problem. I have to keep an eye on the alligators while I am doing this because the location is in the Everglades. No problem. The only problem I am facing is that I have hard time focusing at the stars because the viewfinder is black. (It is 1:00am at night after all.... )

I manually focus at infinity and the stars are out of focus.

I have tried to use the screen in video mode after increasing ISO. No luck. Even the screen on the back of the camera is dark so I am not be able to see the stars for proper focusing.

My question: How do you focus in total darkness? Did I miss something?

I've had good luck presetting manual focus on the short vertical line to the left of the infinity symbol on Canon lenses. Maybe someone else can tell you exactly what that focal point is called...

Most AF lenses go past infinity. The easiest way is to find a bright object (moon, bright star, streetlight, headlight, etc). Turn on live view, and max zoom on that object. Then manually focus on it to make it as small as possible. It should shrink to a point, and then start to grow again, so find the sweet spot in between. Then don't touch it all night...

paul3221 wrote in post #17133214
Most AF lenses go past infinity. The easiest way is to find a bright object (moon, bright star, streetlight, headlight, etc). Turn on live view, and max zoom on that object. Then manually focus on it to make it as small as possible. It should shrink to a point, and then start to grow again, so find the sweet spot in between. Then don't touch it all night...

I have tried. life view doesn't work because it is so dark. Even after turning it to the highest iso....

paul3221 wrote in post #17133214
Most AF lenses go past infinity.

Seems odd, but its perfectly true.

I've found it almost impossible to focus on a star at night, either optically or live view. The best I can do is to focus during the day, and mark the lens setting, or tape it in preparation for the night shots.

seres wrote in post #17133407
I've found it almost impossible to focus on a star at night, either optically or live view. The best I can do is to focus during the day, and mark the lens setting, or tape it in preparation for the night shots.

This is what I am going to do! Did you focus on the sun and marked it?

This is the focus point I was talking about. I've had good success pre-focussing in the dark on this line. If you're incorporating something in the foreground, I would suggest combining images in post-processing.

oharing wrote in post #17133482
This is what I am going to do! Did you focus on the sun and marked it?

I do not recommend focusing on the sun, even through live view - you'll either destroy your eyes or your camera or both! A distance lamp post should be enough.

danialsturge wrote in post #17134000
I do not recommend focusing on the sun, even through live view - you'll either destroy your eyes or your camera or both! A distance lamp post should be enough.

NEVER point the camera at the sun! Yes, a distant object is fine for infinity focus.

I am always able to see the stars &/or moon in liveview. Even if it is completely dark.

- I always use liveview, not video mode.
- Exposure simulation is on.
- Pick a wide open aperture with a highish iso and a slow shutter speed.
- I always have it on a tripod
- As was mentioned above, rotate the focus ring until the stars are at their smallest.

flunky51 wrote in post #17133611
This is the focus point I was talking about. I've had good success pre-focussing in the dark on this line. If you're incorporating something in the foreground, I would suggest combining images in post-processing.

I see! Thanks!

seres wrote in post #17134069
NEVER point the camera at the sun! Yes, a distant object is fine for infinity focus.

Awesome! Thank you guys!

ozzmodan wrote in post #17134517
I am always able to see the stars &/or moon in liveview. Even if it is completely dark.

- I always use liveview, not video mode.
- Exposure simulation is on.
- Pick a wide open aperture with a highish iso and a slow shutter speed.
- I always have it on a tripod
- As was mentioned above, rotate the focus ring until the stars are at their smallest.

Thanks! What is exposure simulation? I am sorry for the silly question.

I remember struggling once, only to find the lens cap was still on.